Modeling And Controller Design Of Network Cascade Control System And Multi Closed-loop Cyber-physics System

As a product of the information technology era,cyber-physical systems derived from networked control systems integrate multi-dimensional and complex disciplines such as information networks,physical environments,and computer computing and have the characteristics of autonomy,distribution,real-time,and high security and reliability.Networked control systems and cyber-physical systems use information networks as a medium to transmit information perception of the physical world,integrate computing,decision-making,and execution,and achieve control requirements adjustment for components in the physical world.The networked control system architecture is the foundation for the stable and efficient operation of the system.It is also a requirement for a high degree of cross-integration of information networks,physical environments,and computer computing.According to the production requirements of industrial process control,this thesis focuses on the complexity of the overall structure analysis for networked control system and cyber-physical system and the difficulty of its system controller co-design.It conducts in-depth research on the modeling and stability of the system and the collaborative design scheme of multiple controllers for the cascade structure and three closed-loop structure commonly used in industry.The effects of network-induced delays and disturbances on the overall stable operation of in networked cascade control systems and three closed-loop cyber-physical systems are considered,and corresponding controller schemes are designed.Finally,the feasibility and effectiveness of various structural schemes are verified through practical cases of marine boiler power generation.The main contents of this thesis are summarized as follows:(1)For networked cascade control systems with information network transmission delay,the stability of systems and the design of its controller are studied.First,according to the system structure commonly used in industry,the traditional and new networked cascade control system model with outer ring information transmission delay are established for the first time.Then,using the stability theory and the related inequality technique,sufficient conditions for the system to be stable are given,respectively.Then,based on the sufficient stability of its system,the schemes of its controller co-design are provided respectively.Finally,the feasibility and validity of the system are verified by a real simulation case.(2)The stability and the design scheme of its controllers are studied for the three-closed loop cyber-physical system with multiple controlled objects.Firstly,according to the structure of systems commonly used in industry,the model for three closed-loop cyber-physical systems is established for the first time.Then,considering the ideal state and the existence of disturbance,the sufficient conditions for the stability of the system and the H_∞multi-controller design scheme are given respectively.Finally,the feasibility and effectiveness of the method are verified by simulation with a case.(3)Aiming at the three closed-loop cyber-physical system with network-induced delay,the system’s stability and the controllers’co-design scheme are studied.Firstly,the model for three closed-loop cyber-physical systems with transmission delay is established for the first time.Then,the sufficient conditions for the stability of the system are derived,and the multi-controllers’co-design scheme for the system is given respectively.Finally,the simulation results are compared with the cascade control system with three controlled plants to verify the effectiveness and practicability of the three closed-loop cyber-physical system with network-induced delay.